The present invention relates to an arrangement for controlling a fluid volume in shape changing elements of seats, in particular vehicle seats.
Shape changing elements in seats, also known as seat inserts, are used for improvement of sitting comfort by individual adaptation of the seat contours of the seats to a seat user and are utilized in so-called multi-contour backs in the vehicle seats also for massaging the seat user.
In a known vehicle seat disclosed for example in German patent document DE 100 63 478 A1, a plurality of shape changing elements formed as air cushions are controlled in a timely offset manner by a control device via a pneumatic control member and lead to massaging of a person which uses the seat with a forward stroke by filling with pressure air and rearward stroke by air evacuation. The air filling and air evacuation of the air cushions is performed by electromagnetic valves. The air cushions are assembled in cushion groups, and in each pressure conduit leading from a pressure air source to a cushion group, a series connection of a 3/2 directional magnetic valve and a 2/2 magnetic valve is arranged. Conventionally, the valves are mounted being assembled into valve blocks. Such valve blocks are very heavy and have great volumes, and are difficult to integrate into the seat.
Another known arrangement is disclosed in the German patent document DE 31 42 833 A1 and has a displacement valve formed as a control slider of a rotary slider. It has a central pressure chamber which is filled from the medium going from a pressure modulator. This rotary slider is substantially cup-shaped and in its side wall has a radial outwardly extending open passage. In this region a seal is placed on the outer surface of the wall of the rotary slider and has a central throughgoing passage coinciding with the passage of the rotary slider. The rotary slider is rotationally displaceable inside of a substantially cup-shaped housing. The cup-shaped housing has a plurality of inner radial passages spaced from one another in a circumferential direction and merging into axial passages with connecting openings for conduits. The inner passages are located axially at a height of the radial passage of the rotary slider. The rotary slider can be turned into different rotary positions. Its passage correspondingly communicates through a throughgoing passage in the sealing ring with an inner passage of the housing, so that fluid located in the central passage chamber can be supplied through this passage connection into the corresponding conduit to the corresponding shape changing element. Also, arrangement that is united with a pressure modulator to form an assembly, has a great dimension and is heavy and requires a lot of space.